Narthecium Ossifragum Research Articles

Nephrotoxicity of Narthecium ossifragum in cattle in Norway.

During the summer of 1992 renal failure was diagnosed in 232 grazing cattle in 85 herds on the west coast of Norway. The salient clinical signs were depression, anorexia and melaena or fresh blood in the faeces; diarrhoea was also commonly observed. The serum concentrations of creatinine, urea, magnesium and phosphorus, and the activities of glutamate dehydrogenase, aspartate aminotransferase and creatine kinase were above normal and the serum calcium concentration was below normal. Post mortem examinations consistently revealed renal tubular necrosis. In some cases there was liver necrosis and also erosions at the base of the tongue, in the oesophagus and in the jejunum and colon. The toxicity was probably caused by the plant Narthecium ossifragum (bog asphodel).

Narthecium ossifragum Associated Photosensitization in Sheep in The Faroe Islands

Hepatogenous photosensitization in sheep is an important problem in various parts of the world. Most photosensitization diseases are associated with ingestion of plant or fungal toxins. The lily, Narthecium ossifragum, has long been associated with photosensitization in lambs in western Norway (Ender 1955, Flaoyen 1993) and in the northern regions of the British Isles (Ford 1964).

Nephrotoxicity and hepatotoxicity in calves apparently caused by experimental feeding withNarthecium ossifragum

Seven calves were fed a mixture of bog plants containing 15 g (wet matter) Narthecium ossifragum per kg live weight for two consecutive days. Their serum creatinine, urea and magnesium concentrations increased, whereas the serum calcium concentration decreased. Histopathological examination of the kidneys of the 5 calves that were killed revealed tubular epithelial cell degeneration and necrosis. There were signs of liver dysfunction in all the calves including increased aspartate aminotransferase (ASAT), glutamate dehydrogenase (GLDH) and gamma-glutamyltransferase activities. All the calves refused to ingest N. ossifragum after 2 days feeding, and their appetite for hay and concentrate was also reduced. It can be concluded that N. ossifragum is nephrotoxic and hepatotoxic to calves.

Nephrotoxicity in lambs apparently caused by experimental feeding withNarthecium ossifragum

Seven lambs were fed a mixture of bog plants containing 15 g (wet matter) Narthecium ossifragum per kg live weight for 10 consecutive days. Their serum creatinine concentration increased from day 1 to 4 but then fell to normal by day 6 after feeding started. In the same animals, the serum magnesium concentration was increased on days 3, 4 and 5. Histopathological examination of the kidneys of 2 lambs killed after being fed 25 g N. ossifragum per kg live weight for one day revealed tubular epithelial cell degeneration and necrosis. There were no signs of disease or distress in the experimental animals and their appetite remained normal throughout the experimental period. It was concluded that N. ossifragum is probably nephrotoxic to lambs.

An experimental investigation of the effects of nitrogen deposition to Narthecium ossifragum

Narthecium ossifragum (L.) Hudson was subjected to artificial deposition events in three experiments. In the first, a laboratory experiment, 1·0 m nitrate significantly decreased the growth of Narthecium, and the shoot and root nitrogen content of the plants was increased in all enhanced nitrogen treatments. In the second experiment, solutes were applied in situ to a relatively unpolluted upland ombrotrophic mire at concentrations measured in cloud water at a polluted site in England. There was no effect on Narthecium tissue nitrogen concentration due to either ammonium or nitrate applied alone but the shoot nitrogen was significantly increased when the ammonium and nitrate were applied in combination. In the third experiment, a piece of upland ombrotrophic mire from a relatively unpolluted site in North Wales was transplanted to a polluted site in northern England. After two years both the shoots and roots of Narthecium present in the mire showed a higher nitrogen concentration in the transplant compared with the control. These data show that nitrogen supply in the southern Pennines is supra-optimal for Narthecium, which implies that in such situations it (and other species with a similar ecological strategy) would be out-competed by more vigorous species. The data from the field experiment at the relatively unpolluted site imply that even there, nitrogen supply is close to supra-optimal for Narthecium.

Seven Years of Change Following Liming ofSphagnumCommunities in Sector Vii of the Loch Fleet Catchment

Abstract In 1986, application of lime within the upper wetland area of sector VII of the Loch Fleet catchment initiated numerous unscheduled small-scale experiments on the vegetation of this heterogeneous terrain. Vegetation changes and erosion were monitored in permanent or relocated plots established in 1987 and 1989 and re-surveyed in 1993, seven years after liming. The most striking early effect, possibly occurring within a few weeks of lime application, was the death of Sphagnum papillosum carpet in soakways within the 2.5 ha area. Some patches of dead material were washed away, but bare surfaces were generally colonised by vascular plants, notably Juncus bulbosus. Effects in moorland and bog communities with dwarf shurbs were more subtle, involving reduction in Sphagnum cover and expansion of Erica teralix, Molinia caerulea, sedges and Narthecium ossifragum, but little change in the frequency of occurrence of Calluna vulgaris.

Identification of insoluble salts of the .beta.-D-glucuronides of episarsasapogenin and epismilagenin in the bile of lambs with alveld and examination of Narthecium ossifragum, Tribulus terrestris, and Panicum miliaceum for sapogenins

Crystalloid material soluble in acetic acid was isolated from the bile of lambs with alveld (a hepatogenous photosensitization disease which develops after grazing Narthecium ossifragum). The main components of these bile extracts were shown by hydrolysis, GC-MS, TLC, LSIMS, 1 H and 13 C NMR, and X-ray analysis to be salts of a 4:1 mixture of episarsasapogenin β-D-glucuronide (1) and epismilagenin β-D-glucuronide (2). The 13 C NMR spectrum of 1 was fully assigned by comparison with the NMR spectra of model compounds. A metabolic route for conversion of the sarsasapogenin saponins of N. ossifragum into 1 is proposed

Bog asphodel (Narthecium ossifragum) poisoning in cattle.

Fifteen cows among a herd of 50 suckler cows and calves rapidly lost body condition and became dull and anorexic after grazing pasture containing bog asphodel (Narthecium ossifragum) during the summer of 1989. The affected cows had evidence of kidney damage characterised by elevated plasma urea and creatinine concentrations. Eleven cows died and diffuse renal tubular necrosis was present in three cows which were examined post mortem. Similar renal lesions were reproduced experimentally by feeding bog asphodel to a healthy calf.

Fungi on Narthecium ossifragum leaves and their possible involvement in alveld disease of Norwegian lambs.

Spores of Pithomyces chartarum (Berk. & Curt.) M.B. Ellis were only rarely seen on leaves of Narthecium ossifragum (L.) Hudson collected in summer from five areas in western Norway in which alveld, a photosensitization disease of lambs, is endemic. Cladosporium magnusianum (Jaap) M.B. Ellis was found on all 118 leaf samples collected in the summers of 1990 and 1991. The hypothesis that P. chartarum contributes to the aetiology of alveld could not be supported, but it is possible that C. magnusianum may have a role in the causation of the disease.

The Part Taken by Cleistogamy in Narthecium ossifragum Reproductive Strategy

The floral biology, breeding system and pollination ecology of Narthecium ossifragum (Liliaceae) were analysed in the high Ardennes, Belgium, during the summer 1986. A new kind of pollination for this species was noticed: some nower buds don’t open but set seeds. Observations substantiate the claim of self-fertilization which is connected to pseudocleistogamy. A probable cause for this bud pollination is drought. Nevertheless, its efficiency and frequency are very low.

Failure to induce toxicity in lambs by administering saponins from Narthecium ossifragum

It has been suggested that saponins produced by Narthecium ossifragum (Bog asphodel) may be the direct cause of the toxicity leading to the hepatogenous photosensitivity disease alveld seen in Norwegian lambs. Lambs fed large quantities of freeze-dried N. ossifragum did not develop alveld. Chemical investigations on the freeze-dried material and fresh N. ossifragum showed no difference in their saponin content. These results indicate that alveld is not caused solely by the saponins produced by N. ossifragum.

Saxosterol, a new dihydroxy cholesterol from Narthecium ossifragum

A new sterol, (22 R)-cholest-5-ene-3β,16ξ,22-triol, designated saxosterol, has been isolated from N. ossifragum. In the plant saxosterol occ

Alveld-Producing Saponins

The phototoxic lamb disease alveld, prevalent in South-Western Norway, is caused by ingestion of Narthecium ossifragum. Earlier studies have shown that peroral administration of large amounts of crude saponins from this plant elicits the disease. Such saponins have now been purified further by 2 different methods (A and B). Two A type preparations resulted in alveld when fed to 2 lambs. The most highly purified preparation (type B) did not cause alveld in the 2 lambs tested. Lambs vary, however, in their susceptibility to the disease. Both types of preparations led to increases in serum aspartate aminotransferase, bilirubin and 5′-nucleotidase in rats when injected intraperitoneally in amounts of 50 or 100 mg/kg body Weight. Cannulation of the bile duct showed that injected saponins reduced both the volume of bile and the amounts of bilirubin and bile acids excreted. Histological changes seen in the light microscope were, except for the most peripheral parts of the liver, hardly noticable. These observations support the view that saponins are the liver-toxic agents responsible for alveld. The possibility is discussed that the effect arises through a change in the lipid environment of carrier-mediated transport systems.

Bog asphodel (Narthecium ossifragum) as a cause of photosensitisation in lambs in Norway.

In a five year experiment, 195 lambs and their dam were kept on four plots of wet moorland rich in the plant Narthecium ossifragum. The plots were top-dressed with calcium and, or, phosphorus, or given no treatment. After three years, the plant disappeared from the plots to which phosphorus had been applied, but remained where calcium only had been used. The saponin content of the plant appeared to be uninfluenced by the type of top-dressing or time of year. Photosensitisation (alveld) occurred on all plots during the first three years. During the fourth year the disease occurred only where the plant persisted. In the fifth year the disease did not occur on any plot. Alveld was produced in two lambs by the repeated administration of large quantities of saponin preparations from N ossifragum. Lambs of haemoglobin type AA were significantly more resistant to the disease than lambs with type BB. In nearly half the cases, the bromsulphthalein liver function test indicated a susceptibility to alveld up to seven days before the appearance of clinical signs. Increased bromsulphthalein retention was more common amongst AA lambs than BB lambs, but nearly all the BB lambs developed alveld, and only a few of the AA lambs. The differences were significant.

Changes in Two High Altitude Blanket Bogs after the Cessation of Sheep Grazing

(1) A 15-year botanical study on the effects of excluding sheep from 350-m2 fenced areas on two high-altitude Eriophoretum blanket bogs has been carried out on Moor House National Nature Reserve. (2) The poverty of the bogs is stressed; they were species-poor, of little cover, and erosion was active. (3) Climate had previously been considered the main factor controlling the vegetation, but the importance of sheep grazing soon became apparent. After 14-year protection both bogs had undergone major changes in species composition, pattern of vegetation and structure. (4) Calluna vulgaris, from an early position of scarcity, grew to dominate parts of each exclosure, whilst the cover of Empetrum nigrum trebled in the same period. However, Empetrum nigrum, after having dominated more than 10% of each bog in the mid-term of the study, finally gave way to Calluna vulgaris. (5) Rubus chamaemorus and Narthecium ossifragum (the latter present only in one exclosure) increased spectacularly, but Trichophorum cespitosum became intermingled in the developing vegetation and lost its distinctive homogeneous community pattern. (6) Leafy liverworts, in particular Diplophyllum albicans, a constant of the high-level Eriophoretum facies, declined; the colonization of bare peat was slow. (7) Botanical composition, structure and density altered in the direction of Calluneto-Eriophoretum, a move recommended as an improvement for wildlife and possibly agriculture. To test the agricultural benefit would require further experiments.

Alveld-Producing Saponins

Stabursvik (1959) described the saponin fraction of Narthecium ossifragum as a sarsasapogenin glycoside with the structure arabinosegalactose-xylose-glucose-sarsasapogenin. In a renewed study of the phototoxic lamb disease alveld, in which this saponin has been implicated (Ender 1955), we have looked more closely at the saponin fraction. We find that there are two saponins, one major and one minor. Both have a branched trisaccharide on C-3 of the sapogenin. Galactose is directly attached to C-3 in both saponins. The major saponin has glucose and arabinose attached to galactose, the minor saponin has glucose and xylose. We suggest the names narthecin and xylosin for the spirostanol form of these two saponins. In fresh juice from leaves we find little narthecin, however. Most of the saponin is present in the furostanol form, with glucose on C-26. Enzymatic hydrolysis showed this glucose to be bound as a β-glucoside. From specific rotations in partial hydrolysates we conclude that the saccharide on C-3 is a β-D-glucoside, α-L-araboside, β-D-galactoside.

The Growth of Narthecium Ossifragum in Some Southern English Mires

Summerfield (1973) compared the growth of Narthecium ossifragum (L.) Huds. in several British mires with that in southern Swedish mires (Malmer 1962b), and suggested that its growth on the valley mire on Roydon Common, Norfolk, was 'approaching the upper limit of its performance in Great Britain'. Summerfield & Rieley (1975) related the growth of N. ossifragum on these mires to mineral nutrient supply. However, because these workers did not examine mires further south than Roydon Common, Norfolk, and Wem Moss, Shropshire, measurements are reported in this paper on the growth of N. ossifragum from five more southerly valley mires in Berkshire, Hampshire and Surrey. On one productive mire, on Hazeley Heath, Hampshire, attempts have been made to associate local variations in the performance of N. ossifragum with soil nutrient and oxygen supplies. Two nutrient addition experiments are also reported.

Observations on the Performance of Narthecium Ossifragum (L.) Huds. and Phragmites Communis Trin

In the course of a study of the distribution of vegetation at Roydon Common, Norfolk (Daniels & Pearson 1974) it became apparent that there was considerable variation in the height, density and flowering capacity of several species, depending upon their location within the site. This variation was particularly noticeable in the case of Narthecium ossi/ragum* and Phragmites communis, two species whose ranges overlapped to some extent. It was decided to investigate these visual differences in relation to measures of standing crop and of the chemical status of peat waters. Some measures of the performance of Narthecium ossifragum, for both this site and a number of others in Britain, were given by Summerfield (1973). He interpreted his figures as indicating that, at Roydon, this species approaches its upper limit of performance in Britain. However, J. Miles (unpublished) contests this conclusion on the basis of results obtained from a number of sites in southern England where standing crop figures are comparable with those obtained by Malmer (1962a, b) for Swedish sites, and concludes that the nutrient status of the peat water has relatively little influence, the major determinant of performance being the degree of oxygenation of the root zone. Haslam (1971a, b) discussed factors affecting the performance of Phragmites communis in both monodominant stands and mixed ones. She suggested that different biotypes exhibit different potentials for growth and density, though major changes in habitat conditions may alter these biotypes. Within mixed stands she concluded that, whilst limiting levels of certain nutrients may be responsible for poor performance at the more oligotrophic end of the plant's range, elsewhere performance is greatly influenced by competition from other species, especially in relation to shading capacity and tolerance.

Relationships between Mineral Supply and Growth of Narthecium Ossifragum (L.) Huds. on Mire Ecosystems

Relationships between Mineral Supply and Growth of Narthecium Ossifragum (L.) Huds. on Mire Ecosystems

The Growth and Productivity of Narthecium Ossifragum on British Mires

Mire ecosystems are of considerable importance on the global scale and cover at least 660 million acres (276 x 106 ha) of the world's surface. Of this vast area, that present in Great Britain accounts for 9/%, 11 % and 14% of the total area of Scotland, England and Wales, and Ireland respectively (Davis & Lucas 1959). Though considerable attention has been afforded to mire systems, their natural productive capacity is largely unknown (Gorham 1957). One of the aims of the International Biological Programme is to gain an understanding of the productivity of vegetation on a world scale. It has been suggested that mire ecosystems offer the best units for the study of natural vegetation in relation to mineral supply and, therefore, could represent basic units for comparison of the productivity of other vegetation types (D. J. Bellamy & J. O. Rieley, unpublished, 1965). With regard to the productivity of natural vegetation, there are several major questions to which answers should be sought (Jervis 1969):